My 2005 Ford Freestar with 164k miles experiences a high pitched whistling noise coming from the front end after a few minutes of highway speed driving. It sounds like a tea kettle whistle. It starts out as a quick pulsed whistle then moves to a solid whistling noise. I’ve heard it driving straight and turning. The sound pulsates if I turn the steering wheel slightly to the left or right but seems to occur more when I turn right. The sound does not occur if van is not in motion and will stop just before car comes to rest at a stop. Three repair shops have looked at this and none of them can replicate the sound while van is on a lift but one shop did hear it during a test drive. All three shops have been unable to locate / diagnose this whistling noise. They all state brakes are in very good shape. I use this van for my small business (The Happy Kid Traveling Company) and could really use some help with the diagnosis. THANK YOU!
Ask the shop to diagnose it on a ‘‘road force balancing’’ machine. If they don’t have one they need to take it somewhere that does. This machine will spin the wheels on the car so as to see if it’s wheel related.
A low brake pad warning spring might sound like a whistle. Could also be in the rear as sound radiates.
It may be just that, a whistle. By that I mean some change has occurred to something on the car which has created a surface that will make a whistle-like sound as the air move past it. It only whistles while the car is moving b/c there is no air moving past when the car is stopped. The wind is needed for the sound to occur in other words.
If I recall correctly, a while back a caller on the Car Talk show said they noticed a sound like this, and found it was caused by the rack on top of their truck. A small piece of plastic which had blocked the end of a pipe had fallen off, creating a natural whistle. So look for something which has changed which receives a lot of airflow, like a tear or loosening of the windscreen under the front of the car, the radio antenna, the windshield wipers, etc.
There’s a gadget some mechanics have that could be useful too. I’ve never seen one, but I think it has a bunch of microphones which can be placed at various spots on the car, and which communicate wirelessly to a headset the driver wears. The driver switches from one microphone to the next to find which one has the sound the loudest. Can be used to narrow down the location. Best of luck.
Ths is likely a bad wheel bearing seal, which is why the sound changes when you turn the steering wheel…and why the sound can’t be heard while the van is on a rack.
I don’t think it’s wind noise because you said it whistles even at very low speed (until it comes to a stop). There isn’t enough wind speed at a few mph to cause an aerodynamic whistle.
Have the wheel bearings checked. One of them is bad. You said it seems to be worse when you turn right, which would make me suspect the left bearing. You will need to replace the entire hub assembly, not just the bearing,or the noise will not go away.
http://www.aboutautomobile.com/Complaint/2005/Ford/Freestar/Wheel
http://www.fixya.com/cars/t8370540-2005_ford_freestar_high_pitched